1. Field of the Invention
The present invention relates to a lens interchangeable camera. More particularly, the present invention relates to a lens interchangeable camera having a camera body and a lens unit for mounting on the camera body, and capable of preventing entry of dust or other wanted material even at the time of exchange.
2. Description Related to the Prior Art
A digital still camera is widely used, and includes an image pickup device or CCD image sensor for photographing an image. A lens interchangeable type of camera includes a camera body and a lens unit secured to the camera body in a removable manner. A mount mechanism is disposed in the camera body for connection with the lens unit. An exposure opening is formed in the center of the mount mechanism for entry of object light from the lens unit into the camera body. When the lens unit is removed from the camera body for exchange, inner elements of the camera body appear through the exposure opening. If dust enters the exposure opening and deposits on a sensor surface of the image pickup device in the camera body, image quality of recorded images will be lowered. A user must handle the lens unit carefully and exchange the lens unit rapidly by considering
JP-A 6-167670 discloses a camera having a photographing optical system movable between a front position and a rear position. When a protection cover for protection from dust is moved to the closed position, the photographing optical system is moved to the rear position. When the protection cover is moved to the open position, the photographing optical system is moved to the front position. The protection cover in the closed position is used for preventing deposition of dust by covering the photographing optical system.
However, environment of various conditions is possible in exchange of the lens unit, for example an outdoor condition, a dirty condition with much dust even in an indoor state. Dust or other unwanted material may enter the camera body through the exposure opening in the exchange no matter how quickly a user handles the lens unit. A camera in JP-A 6-167670 is a type different from a lens interchangeable type. Although dust is prevented from depositing on the photographing optical system in the document, there is no prevention of entry of dust in the camera body.